Automatic alarm system



Nov. 19, 1963 BARRETT ETAL 3,111,656

AUTOMATIC ALARM SYSTEM Filed Feb. 26, 1960 2 Sheets-Sheet J.

i 60 Isa 10 T RANSMITTER z swaa'w NEAL H. FULLER BY W3:

ATTORNEY Nov. 19, 1963 N. A. BARRETT ETAL 3,111,656

AUTOMATIC ALARM SYSTEM Filed Feb. 26. 1960 2 Sheets-Sheet 2 FIG. 2 1

x RECEIVER 2 JNVENTOR NAT A. BARRE T NEAL H. FULLER A" M! Y {in v ar 8ATTORNEY United States Patent 3,111,656 AUTOMATIC ALARM SYFrTEM Nat A.Barrett, 663 Barnett St. NE, and Neal H. Fuller, 668 Kennolia Drive SWboth of Atlanta, Ga. Filed Feb. 26, 1960, Ser. No. 11,241 7 Claims. (Cl.340-415) This invention relates to automatic alarm systems and moreparticularly to an alarm system of the type which transmits a codesignal from the point of occurrence of a predetermined condition, suchas a rise in temperature as the result of a fire, to a central alarmstation whereby both audible and visible alarms are energized and arecord of the alarm call is made.

It is, therefore, an object of this invention to provide a fire alarmsystem wherein a local temperature responsive code transmitter isenergized by the occurrence of a fire to transmit a predetermined codesignal representative of the location of the fire to a central alarmstation.

Another object of this invention is to provide a novel code keyingactuator and circuit in the local temperature responsive transmitter.

Another object of this invention is to provide a fire alarm systemhaving a local temperature responsive transmitter for sounding an alarmat a remote station simultaneously with a local alarm.

Still another object of this invention is to provide a fire alarm systemhaving at least one local condition responsive transmitter and a remotereceiver at a central alarm station wherein the local transmitterincludes a code sequence keying device comprising a pattern perforatedbelt for operating a set of keying contacts to effect the transmissionof a predetermined code sequence in response to the occurrence of a fireor other predetermined condition.

Still another object of this invention is to provide a tire alarm systemhaving a radio receiver located at a central alarm station for receivingcoded signals from remote locations for indicating the presence of afire or the like at any particular one of the locations.

Still another object of this invention is to provide a fire alarm systemof the local transmitter-central receiver type wherein the receiver hasa novel energiza-tion cycle for receiving coded alarm signals, providingan audible and visible indication of their reception and automaticallyrecording that portion of the alarm code which designates the locationof the fire.

Still another object of the invention is to provide a fire alarm signalsystem of the local transmitter-central receiver type wherein inresponse to the reception coded alarm signal transmitted in response toa fire at the location of one of a plurality of local transmitters, thecentral receiver will be automatically switched-on to energize audibleand visible alarms at the central station and simultaneously energize alocal recording means for a predetermined time period following whichboth the alarms and the recording means are automatically deenergized.

These and other objects of the invention will become apparent byreference to the following specification and ice means which modulatesthe output of the local transmitter to effect the transmission of aradio frequency code signal to a central alarm station. At the centralstation a radio receiver is provided which after a predetermined callcode delay period included in the code signal energizes a plurality ofalarms at the central station and switches on. a tape recorder or thelike to record that part of the code signal which gives the location ofthe occurrence of the fire or other detected condition and then after apredetermined time de-energizes the alarms and the recorder.

Transmitter Referring in detail to the drawings, FIGURE 1 shows a localcondition responsive means including temperature responsive switches 10or the like.

The temperature sensing switches l0 are connected across a pair of leads12 and 14 of which line 12 extends to terminal 16 of a plurality ofcommon terminals 16, 18, 2!} between parallel connected alarm bell 22and electric motor 24. Terminals 1 6 and 18 are interconnected by a line26 between the alarm bell 22 and electric motor 24 which further extendsto one terminal of a relay coil 28 in relay RT. The other terminal ofthe relay coil 28 is connected through a line 3t and a line 32 to theremaining common terminal 20 between the parallel connected alarm bell22' and electric motor 24. Both lines 30 and 32. are connected atjunction 34 through a line 36 to one terminal of the secondary 38 of apower input transformer 40.

The other side of the secondary 38 of the transformer 40 is connectedthrough a line 42 to 'a contact brush 4 which is in sliding contact withthe end face 46 of a conductive rotating cylinder 48 driven, through aconnection not shown, by the electric motor 24.

The circuit through the temperature responsive switches 10 is completedthrough line 14 which is connected to a second contact bnush 5i} mountedin sliding contact with the peripheral surface 52 of the conductivecylinder 48.

The energization of the local transmitter 54 is controlled by thecontacts 56 of the relay which are operated by the energization of theabove described relay coil 28. The relay contacts 56 are located in aline 58 which in cooperation with a line 60 extends from the primaryside 62 of the supply transformer 44 to the power input terminals 64 ofthe transmitter .54.

The transmitter 54 is keyed to transmit a coded alarm signal sequence bythe code sequence generator generally shown at 65.

The code sequence generator 66 comprises a dielectric belt 68 having aplurality of longitudinally spaced perforations 71) therein. Theperforations 76 are of variable size and sequence to represent aplurality of code characters.

The perforated dielectric belt 63 is of the continuous type and ismounted over the conductiverotating cylinder 48 at one end and a springbiased idler cylinder 72 at the other end, whereby the belt 68 istightly stretched between the two cylinders. The cylinder 48 is providedwith sprocket teeth 74 which drive the belt 68 through means of a seriesof cooperating perforations 76 in the belt 68.

Two basic switching functions are performed by the perforated dielectricbelt 68. The first function is to code key the transmitter 54 throughmeans of the perforations 70 which permit a pair of roller type contacts78 to close for variable spaced periods of time as the belt 68 is drivenpast them by the conductive rotating cylinder 48.

The rolling contacts 78 are mounetd one on each side of the belt 68 andare of such a size that they fit within the perforations 70, whereby thecontacts 78 are brought 3 into juxtaposition each time they registerwith one of the perforations "70 The rolling contacts 78 are eachmounted on one of a pair of spring arms 88 fixed, respectively, to eachof a pair of terminal posts 82 whereby the spring bias necessary toeffect a positive electrical contact is provided. The terminal posts 82,and thus the contacts 7-8, are connected through a pair of lines 84 tothe code keying terminals 86 of the transmitter 54. .Thus, when thecontacts 78 are closed, a circuit is completed across-the code keyingterminals 86 of the transmitter '54 and a signal is transmitted from theantenna 88 as long as the contacts 78 remain closed.

After a complete signal cycle has been transmitted by way of-the belt 68andcode-keyed transmitter 54, the second switching function of the belt68 is to de-energize the belt driving motor'24and the local alanm bell22. This istaccomplished by means of a short switching segment 90 whichis a rectangular segment extending outward from the side of the belt 68such that at the end of the code sequence on the belt, the switchingsegment 90 is driven between the sliding contact brush 50 and theperipheral surface '52 of the conductive rotating cylinder 48 to breakelectrical contact therebetween and open the alarm and motor circuit.

Receiver Referring now to FIGURE 2, the receiving means at the centralalarm station includes a radio receiver 94 having an antenna 96 for thereception of the code keyed radio frequency signals from any one of theplurality of local transmitters. Power for energizing the receiver istaken from a pair of power input leads P1 and P2 connected to the powerinput terminals 98.

When a transmittedsignal is detected by the receiver, a relay coil 100of plate relay RP is energized through a pair of lines .102 fromtheoutput terminals 104 of the receiver'94. The magnetic action of theenergized coil 100 causes the contacts 106 of the relay RP to close andcomplete a pair of parallel circuits, to be hereinafter described,across'power'lines P1 and P2.

The first of these circuits is an alarm circuit comprising a'line 108extending from power line P1 through a line 110 to one side of aparallel combination of a visual alarm'112 and an audible alarm 114 andfrom the other side of the alarm combination through a line 116 to theother power line P2.

The second circuit is completed through the line 108 from power line P1to a line 118which is connected to onewside of a first timing motor 120which is connected at its other side through a line 122- to the otherpower line P2.

The timing motor 120 in response to a received signal of predeterminedduration operates a set of contactst124 through a time delay-cam 126 andfollower 128 which cooperates with a'switch closing .detent 1138 on thecam 126 to close the contacts 124.

When the contacts 124 close, a circuit is completed from power line P2through line 122 and switch contacts 124, line 132, relay coil 134 andline 136 to power line 'P1, whereby the relay coil .134 of the recorderrelay R 138 to one of the motor terminals 142 of the tape recorder. Theother motor terminal is connected through a line 144 to the other powerline P2.

The other of the circuits completed through the contacts 13-8 of therelay RR is that of a second timer motor 148. The circuit extends frompower line P1, through line 136, contacts 138, line 146, second timermotor 148 and line 150 to the other power line P2.

The second timer motor 148 controls the actuation of a pair of releasecontacts 152 after a suitable delay through a time cam 154 driven by themotor 148. A switch closing 'detent 156 is provided on the cam 154 toengage a cam follower 158 and thereby close the release contacts 152.

The release contacts 152, upon closing, complete a circuit from onepower line P1 and line 160 through a latch release relay coil 162.included in the :recorder relay RR and thence through line 144 to theother .power line P2. The energization of this relay coil releases thelatch means (not shown) holding the contacts 138 of the relay R inclosed position and aliowsthem to open, thus shutting off the recorder14!) after a period of time determined by the second timing motor andswitch combination 14815-2.

Power for the playback amplifier in the-tape recorder is provided by apair of lines 1164 connected between -amplifier power supplytenminals1'66 on the recorder 140 and the power lines Pil and P2.

Once the recorder has been energized, the signals to the recording headthereof are conductedfrom output terminals 168 of the transmitter 94through a pair of leads 170 to the recording head input terminals 1172on the recorder 140.

Operation utends from the switch 10 through line "12 to common terminals16 and 18 and thence through three parallel branches including,respectively, relay coil 28 of the transmitter energizing relay RT,local alarm bell or other suitable signal device 22, and the code beltdriving motor .24; common terminal 34 on the other side of the parallelcombination described above through line 36, secondary 38 of thetransformer 40, line 42, brush 44, conductive rotating cylinder 48,brush 50 and line 14 back to the temperature detector switch 10.

When this circuit is closed the code belt 68 is in the position shownwith the brush contact 51) in contact with the cylinder 48 just past thepoint where that contact would have been broken by the switching segment90 on the belt 68. This allows maximum use of the available belt length.

Also upon the closing of the secondary circuit the coil 28 of thetransmitter energizing relay RTis energized, causing the relay contacts"56 to close and complete a power supply circuit through lines 58 and60, transformer primary 62 and power input terminals 64 of the transmit-'ter 54 whereby the transmitter is energized and commences to warm up.

Concurrent with the energization of the relay RT the local alarm bell issounded and the belt driving motor 24 is energized. As soon as the motor24 is energized, the

. l the sequence of signal transmission periods of the transmitter '54,are on opposite sides of the unperforated portion of the tape 68 whichat the start of the code cycle is shown extending from the rollers 78over the conductive cylinder 48. Thus, no contact being made, there isno signal transmitted from the transmitter 54.

Since the belt is driven at constant speed, the code symbols aredetermined by the sequence and length of the trains of carrier frequencyalternations which are periodically transmitted in accordance with theperforated sequence on the belt, the length being determined by the sizeof the perforations and the sequence by the relative position thereof.

From the start position, the above defined unperforated area of the belt68 is of such a length as to allow adequate warm up time for thetransmitter 54. A period of thirty seconds, for example, wouldordinarily be more than adequate.

The first perforation in the belt allows the rolling contacts 78 toclose the transmission circuit of the transmitter 54 through theterminals 86 and effect the transmission of the carrier frequency wavetherefrom for a definite predetermined period such as, for example, fourseconds. The function of this signal is to energize a time delay relayset for a minimum response time in the radio receiver located at thecentral alarm station to be later described with respect to FIGURE 2.

'Next on the belt, are two identical sets of perforations inpredetermined sequence which all-ow the rolling contacts 7 8 to key thetransmitter 54 and eifect the transmission of duplicate code sequenceswhich identifies, at the receiver in the central alarm station, thelocation of the particular local transmitter 54. The sending induplicate is to avoid error at the receiver.

-As soon as the first signal of the code sequence, as defined inconjunction with the operation of FIGURE 1, is received by the radioreceiver 94 in FIGURE 2, the out put of the receiver through terminals104 and lines 102 energizes relay coil 100 of the plate relay RP,closing contacts 106 and energizing the first timing motor 120. If thereceived signal is truly the first of the code sequence from one of thelocal transmitters as shown in FIGURE 1 associated with the centralalarm station of FIGURE 2., the first timing motor 120 will be energizedfor the, as stated in the above example, four second duration of thesignal, which is the time delay suflicient to bring the contact detent130 on the cam i126 driven by said motor 120 into active engagement withthe cam follower 1 28 and will thereby close switch contacts 124.

'Simultaneousl the contacts 106 of the plate relay RP also close thecircuits through the audible and visible alarm means 114 and 112,respectively, to notify the operator of the central station that analarm signal is being received.

If the first timing motor 120 is sufiiciently energized to close thecontacts 124, then a circuit is thereby completed which energizes thecoil 134 of the tape recorder energizing relay RR whereby contacts !138thereof are caused to close and be latched in closed position by a latchmeans not shown.

The closing of contacts 138 of the recorder energizing relay RR turns onthe tape recorder 140 in preparation for the reception of thetransmitter location identifying code sequence. This sequence is broughtinto the recording head terminals 17 2 of the recorder over lines 170from the output terminals 168 of the receiver.

Concurrent with the energization of the tape recorder 140, the closingof contacts 138 completes the circuit through the second timing motor148 which starts a time delay cycle that determines the length of timewhich the recorder 140 remains energized. This delay is calculated to besufficient to record both of the duplicated code sequences from thetransmitter.

As soon as the second timing motor 148 drives the cam 154 to theposition wherein the cam detent 156 ena 6 gage-s the follower 158 andcloses the contacts 152, a circuit is completed through the latchrelease relay coil 162. Thus, the latch means, not shown, holding thecontacts 138 of the recorder relay RR is released by the energization ofthe latch release coil 162 and the contacts 138 are allowed to open.This de-energizes the recorder and completes the transmit-receive cycleof the alarm'systemt.

The recorded location signal may now be played back and decoded if thesignal could not be decoded from the intermittent buzzing of the audiblealarm 11-4 \or the flashing of the visible alarm 112. A permanent recordof alarm calls is also kept by the recorder for administrative purposes.

' It is emphasized here that the recorder is only energized by a properlength code character preceding the location sequence whereby spuriousor improper signals will not be recorded.

As can be seen from the foregoing specification and drawings, thisinvention provides a simple, readily adapt able and foolproof alarmsystem. It is to be understood that the embodiment shown and describedherein is for the purpose of example only and is not intended to limitthe scope of the appended claims. I

What is claimed is:

1. A condition responsive alarm system comprising a plurality of radiotransmitters placed in a respective plurality of localities adapted tobe individually energized in response to a predetermined condition atthat respective locality to transmit a code signal sequence including acontinuous alert signal having a predetermined time interval and a pairof duplicate sequential signal groups indicative of the location of theenergized transmitter at the locality of said predetermined condition,and a central alarm station common to said plurality of transmitterscomprising a radio receiver for said transmitted code sequence, firstrelay means connected across a first set of output terminals of saidreceiver actuated by said receiver upon the reception of signalsthereby, a pair of power lines, alarm means connected across said powerlines by said relay when said relay is energized to indicate thereception of a signal, and a recording means for recording the duplicatelocation sequence of the transmitted alarm signal comprising, firsttiming means energized by said first relay and fully responsive only toa continuous signal over the minimum time interval of said continuousalert signal from said transmitter, second relay means, switch meansactuated by said first timing means to energize said second relay meansin response to the reception of said continuous alert signal, arecorder, latch controlled switch means actuated by said second relaymeans for connecting said recorder in circuit with said power lines toenergize and maintain said recorder in an energized state, second timingmeans energized by said latch controlled switch means for an effectivetime interval sufiicient to receive said pair of duplicate sequentiallocation signal groups, whereby said signal groups may be recorded bysaid recorder, third switch means actuated by said second timing meansat the end of said effective time interval, and releasing means for saidlatch controlled switch actuated by the closing of said third switchmeans to release said latch controlled switch to open position wherebysaid recorder is deenergized.

2. In a condition responsive alarm system including a plurality of radiotransmitters placed in a respective plurality of locations adapted to beindividually energized in response to a predetermined condition at thatrespective locality to transmit a code signal sequence including acontinuous alert signal having a predetermined time interval and a pairof duplicat sequential signal groups indicative of the location of theenergized transmitter at the locality of said predetermined condition, acode keying means for each of said transmitters comprising, an outputkeying circuit, a power supply, a condition responsive switch means, anelectric motor connected across inder, a perforated code belt on saidcylinders and driven said first cylinder, and a pair of contacts locatedone on either side of'the web of said belt incooperation with the codedperforations on said belt and connected to close 'the output keyingcircuit of said transmitter whereby upon the occurrence of a perforationsaid contacts close saidkeying circuitand energize said transmitter totransmit a signalfor a period of time determined by the lengthof saidperforation.

3. The device as described in claim 2 including a relay operated switchconnected in parallel with said motor and simultaneously actuatedtherewith whereby said. transmitter is connected to said power supply.

4. The device as described in claim 2 including an alarm means connectedin parallel with. said motor and simultaneously actuated therewithwhereby a local indication of said predetermined condition is provided.

5. In a condition responsive alarm system including a plurality of radiotransmitters placed in a respective plurality of locations adapted to beindividually energized in response to a predetermined condition at thatrespective locality to transmit a code signal sequence including acontinuous. alert. signal having a predetermined time interval and apair of duplicate sequential signal groups indicative of the location ofthe energized transmitter at the locality of said predetermined.condition, a code keying means for each of saidtransmitters comprisingan output keying circuit, a power supply, a condition responsive switchmeans, an electric motor connected across said power supply through saidswitch means whereby saidmotor is energized upon the occurrence ofapredetermined. condition, a first cylinder of'electrically conductivematerial rotatably drivenby said motor and connected in circuittherewith by a pair of brushes contacting one on the periphery and oneon the end face of said cylinder, a second cylinder spaced from saidfirst cylinder, a perforater code belt on said cylinders and driven bysaid first cylinder, and a pair of contacts located one on either sideof the web of said belt in cooperation with the coded perforations onsaid belt and connected to close the output keying circuit of saidtransmitter whereby upon the occurrence of a perforation said contactsclose said keying circuit and energize said transmitter to transmit asignal for a period of time determined by the length of saidperforation, said belt having a protruding switching segment on one edgethereof located at the end of the perforated code sequence thereonadapted to be positioned between said. brush contacting the peripheralsurface of said first. cylinder and said surface whereby at. thecompletion of the transmission of said code sequence, said switchingsegment breaks the contact between the said' brush and the said surfaceto de-energize said motor and prevent further signal transmission.

6. In an automatic alarm system having a plurality of radio transmitterslocated at a respective. plurality of localities for individuallytransmitting a code signal sequence comprising an alert signal and alocation sequence in response to a predetermined condition at aparticular locality identifiediby said location sequence, a centralalarm station responsive to the transmitted code signals from any one ofsaid transmitters comprising a. radio. receiver, recording meansconnected with said receiver for recording said location sequence ofsaid transmitted signal, and means connected intermediate said receiverand said recorder selectively responsive to the output of said" receivercomprising a first time delay means selectively responsive to said alertsignal to energize said recorder, and second time delay means energizedby said first means simultaneously with the energization of saidrecorder to maintain said recorder'in an energized condition for aperiod of time sufiicient to record said location sequence.

7. The invention defined in claim 6, wherein said central alarm stationfurther includes a code signal sequence responsive alarm means connectedto the output of said receiver and energized thereby in response to thereception of said code signal sequence, to provide an audible andvisible indication of said location sequence simultaneously with. therecording thereof.

References Cited in the file of this patent UNITED STATES PATENTS2,447,752 Hathaway Aug. 2, 1948' 2,552,788 Hoover May 15, 1951 2,656,528Savino Oct. 20; 1953 2,673,975 Kearney et a1. Mar. 30, 1954: 2,899,674Sierer -Aug. 11, 1959

6. IN AN AUTOMATIC ALARM SYSTEM HAVING A PLURALITY OF RADIO TRANSMITTERSLOCATED AT A RESPECTIVE PLURALITY OF LOCALITIES FOR INDIVIDUALLYTRANSMITTING A CODE SIGNAL SEQUENCE COMPRISING AN ALERT SIGNAL AND ALOCATION SEQUENCE IN RESPONSE TO A PREDETERMINED CONDITION AT APARTICULAR LOCALITY IDENTIFIED BY SAID LOCATION SEQUENCE, A CENTRALALARM STATION RESPONSIVE TO THE TRANSMITTED CODE SIGNALS FROM ANY ONE OFSAID TRANSMITTERS COMPRISING A RADIO RECEIVER, RECORDING MEANS CONNECTEDWITH SAID RECEIVER FOR RECORDING SAID LOCATION SEQUENCE OF SAIDTRANSMITTED SIGNAL, AND MEANS CONNECTED INTERMEDIATE SAID RECEIVER ANDSAID RECORDER SELECTIVELY RESPONSIVE TO THE OUTPUT OF SAID RECEIVERCOMPRISING A FIRST TIME DELAY MEANS SELECTIVELY RESPONSIVE TO SAID ALERTSIGNAL TO ENERGIZE SAID RECORDER, AND SECOND TIME DELAY MEANS ENERGIZEDBY SAID FIRST MEANS SIMULTANEOUSLY WITH THE ENERGIZATION OF SAIDRECORDER TO MAINTAIN SAID RECORDER IN AN ENERGIZED CONDITION FOR APERIOD OF TIME SUFFICIENT TO RECORD SAID LOCATION SEQUENCE.